Air bearing turbo cooling air flow regulating device

Abstract

A cooling air flow regulating device for controlling the flow of cooling air to an air bearing may comprise a housing with a piston and a spring disposed within. When the pressure of the cooling air is high, the piston is forced out of the path of the cooling air and into an open position. As the pressure of the cooling air decreases, the spring forces the piston back into the path of the cooling air, effectively blocking the flow of cooling air to the air bearing. The cooling air flow regulating device of the present invention may be useful for controlling the cooling of air bearings in turbochargers of turbocharged engine, where at low engine speed, cooling air is not required for air bearings. Methods for using the cooling air flow regulating device of the present invention are also provided.

1. A method of cooling an air bearing comprising the steps of:
 providing air bearing cooling air, the air bearing cooling air comprising a pressure P 1 ; 
 flowing the air bearing cooling air through a cooling air passage as a cooling air flow into a cooling air flow regulating device, the cooling air flow regulating device comprising a piston and wherein the piston is in a closed position, blocking the flow of air bearing cooling air through the cooling air flow regulating device; 
 increasing the pressure of the air bearing cooling air to P 2 ; 
 forcing the piston to move in an axial direction, orthogonal to a direction of the cooling air flow immediately upstream of the piston, so that the piston is moved outside of the cooling air passage by the increased pressure P 2 , thereby allowing at least a portion of the air bearing cooling air to flow to the air bearing both linearly through the cooling air flow regulating device and parallel to the cooling air flow immediately upstream of the piston; and 
 cooling the air bearing. 
 
     
     
       2. The method of  claim 1  wherein the step of cooling the air bearing cools an air bearing of a turbocharger of a turbocharged engine. 
     
     
       3. The method of  claim 2  wherein the cooling air pressure is increased by increasing engine speed of the turbocharged engine. 
     
     
       4. The method of  claim 3  wherein the engine speed is increased to at least about 40% of maximum operational engine speed to provide pressure P 2 . 
     
     
       5. A cooling air flow regulating device comprising:
 a housing, wherein the housing comprises an air inlet and an air outlet, wherein the air inlet and air outlet form a cooling air passage for holding the cooling air flow having an air pressure therein; 
 a piston, the piston being disposed in the housing and wherein the piston is movable between a first position where a side portion of the piston is blocking cooling air flow through the cooling air passage and a second position outside of the cooling air passage; 
 a receiving cavity for receiving a portion of the cooling air flow, the receiving cavity providing the air pressure of the cooling air flow to a bottom portion of the piston; 
 an actuating device, wherein 
 the actuating device keeps the piston in the first position when the air pressure in the receiving cavity is insufficient to move the piston to the second position; and 
 the actuating device allows at least a portion of the cooling air flow to move both linearly through the cooling air passage at the piston and parallel to the cooling air flow immediately upstream of the piston when the air pressure in the cooling air passage is sufficient to move the piston to the second position. 
 
     
     
       6. The cooling air flow regulating device of  claim 5  further comprising a seal, the seal being circumferentially disposed around the piston. 
     
     
       7. The cooling air flow regulating device of  claim 6  wherein the seal is an o-ring. 
     
     
       8. The cooling air flow regulating device of  claim 6  wherein the seal is a diaphragm. 
     
     
       9. The cooling air flow regulating device of  claim 5  wherein the actuating device is a spring. 
     
     
       10. The cooling air flow regulating device of  claim 9  wherein the spring is a coil, leaf or bevel spring. 
     
     
       11. The cooling air flow regulating device of  claim 5  wherein the air inlet is in fluid communication with an air charge cooler. 
     
     
       12. The cooling air flow regulating device of  claim 5  wherein the air outlet is in fluid communication with an air bearing. 
     
     
       13. The cooling air flow regulating device of  claim 5  wherein the piston moves between its first and second positions along an axis that is orthogonal to an axis of the cooling air flow immediately upstream of the piston. 
     
     
       14. A cooling air flow regulating device comprising:
 a housing, wherein the housing comprises a vent, an air inlet and an air outlet, wherein the air inlet and air outlet form a cooling air passage for holding the cooling air flow having an air pressure therein; 
 a piston, the piston being disposed between the cooling air passage and the vent; 
 a seal, the seal disposed between the cooling air passage and the vent; 
 a spring, the spring being disposed between the piston and the vent in the housing; 
 wherein the piston has an open position and a closed position responsive to the air pressure of the cooling air flow, wherein the open position allows at least a portion of the cooling air flow to move both linearly through the cooling air passage at the piston and parallel to the cooling air flow immediately upstream of the piston, and wherein the closed position allows a side portion of the piston to block the cooling air flow through the cooling air passage; 
 wherein the spring holds the piston in the closed position until the air pressure of the cooling air flow reaches a pressure sufficient to move the piston to an open position; and 
 wherein the piston moves between its respective positions along an axis that is orthogonal to the direction of the cooling air flow immediately upstream of the piston. 
 
     
     
       15. The cooling air flow regulating device of  claim 14  wherein the seal comprises one of an o-ring and a diaphragm. 
     
     
       16. The cooling air flow regulating device of  claim 15  wherein the diaphragm comprises high temperature reinforced rubber or silicon. 
     
     
       17. The cooling air flow regulating device of  claim 14  wherein the seal comprises high temperature reinforced rubber or silicon. 
     
     
       18. The cooling air flow regulating device of  claim 14  wherein the cooling air flow regulating device is part of a turbocharger. 
     
     
       19. The cooling air flow regulating device of  claim 14  wherein the air inlet is in fluid communication with an air charge cooler and the air outlet is in fluid communication with an air bearing. 
     
     
       20. The cooling air flow regulating device of  claim 14  wherein the cooling air flow regulating device is part of an electric-driven turbocompressor.